Monday, November 30, 2015

Ground-breaking Experiments with Grass

Sometimes second-hand book shops can produce some real gems. A few years ago I found this copy of one of the most notable early 19th. century agricultural works, Hortus Gramineus Woburnensis, hidden in a scruffy, nondescript binding




George Sinclair, the author, was gardener to the 6th. Duke of Bedord at Woburn Abbey from 1807-1825. Under direction from the Duke, and with scientific guidance from Sir Humphry Davey (one of the most famous chemists of the age and inventor of the Davey Lamp, designed to reduce the incidence of explosions on coal mines) Sinclair laid out a large grass garden at Woburn, designed to compare the yields and nutritive qualities of over 200 grass species, and also designed to see how they responded to different soil types and fertilisers.

The introduction to my copy (an 1840s reprint of the 1829 4th. edition) describes how important this research was:

"The time has been in this country (writes the anonymous author of the introduction) when providing  sufficient forage for livestock, in winter was a matter of the greatest difficulty, and great losses were sustained, and many advantages given up, on account of the absolute want of winter fodder. Old turf, suitable either for grazing or the scythe, was supposed to be a creation of centuries; and that a farmer who wished to lay down a meadow in his youth, must see the end of his ‘threescore years and ten’ before he could possibly possess a piece of pasture capable of keeping a score of sheep, or a couple of cows."

He then mentions that " ... farmers, who, becoming slowly sensible to the bad practice of trusting to the sweepings of hay-lofts for their grass seeds …. had begun to purchase pure seeds. " but the varieties and quantities available were limited by the difficulties in collecting them in large quantities. The first to become available was rye grass (Lolium perenne) because its seeds were relatively easy to collect, soon followed by meadow cat's tail Phleum pratense and Cock's foot Dactylis glomerata

Hortus Gramineus Woburnensis describes the results of Sinclair's experiment to compare the agricultural merits of forage grasses and is illustrated with attractive hand-coloured lithographs, showing key recognition features of the most important species described. The first edition, published in 1816, used pressed specimens of the grasses but was far too large and expensive to be of any use to those who would benefit most from the knowledge, so subsequent editions were more compact and illustrated with lithographs.



Aside from the scientific results, Sinclair's text sometimes contains some fascinating snippets of information that give an insight into lost aspects of rural life. He mentions, for example, that culms of crested dog's-tail grass Cynosurus cristatus (above) " are valuable for the manufacture of straw bonnets."  

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Anyone walking today through a meadow with an abundance of this grass might notice how stiff it's culms are (see picture above) - certainly suitable for plaiting into hat material. 

There's an interesting article on straw hat makers of the day on the Jane Austen web site - click here to view. - although I suspect that the hats that Sinclair refers to are much more rough-and-ready affairs.




































The original introduction to the first edition spells out the motives for Sinclair's work:

"Grass..........vulgarly forms one idea; and a husbandman, when he is looking over his enclosure, does not know that there are three hundred species of grass, or which thirty of forty may be at the moment under his eye............... Of the one hundred and thirty-three distinct species and varieties of grass, natives of the British isles, many are of no value to the farmer, while others constitute the foundation of his riches …."

..... and it was these that Sinclair identified in his ground-breaking comparative experiments. He identified the species that were most productive and most nutritious but, perhaps more importantly, recognised that combinations of species in a pasture or meadow can be more productive that single-species monocultures - a finding that has been reinforced by modern research. Darwin referred to these findings in his Origin of Species and in 2002 a research paper in the journal Science (see below for reference) described Sinclair's research as the 'world's first ecological experiment'. 

Sinclair, who conducted much more agrobotanical research (including work on weeds, which I'll write about later) , was highly esteemed in his day and became a Fellow of the Linnean Society. He died at the young age of 47, in 1834. 






































There's one more interesting insight in my copy of Hortus Gramineus Woburnensis, pasted inside the front cover. The book was originally part of the lending library of Newcastle upon Tyne Farmers' Club, and the notice sternly warns of the penalties and draconian fines for not returning the book on time.

Bibliography:

A.Hector and R.Hooper (2002) Darwin and the First Ecological Experiment. Science 295: 639-640.


Thursday, November 26, 2015

Stranglers

In tropical rainforests strangler fig seeds germinate in the tree canopy and send roots downwards until they reach the soil. Then, as their roots grow they strangle the tree that originally supported their seedling stage. You can watch a video of the whole process by clicking here.

Here in our temperate woodlands we don't have anything quite that dramatic, but we do have honeysuckle that sometimes strangles trees from the ground upwards.



When honeysuckle seeds are voided by birds that eat the berries they often germinate close to trees that the birds were perching on. If they can't twine around the tree honeysuckle stems will twist around each other, becoming mutually supportive as these three have, forming a rope-like trunk but ....






... if they can find a sapling tree to coil around, so much the better. This one coiled around a young rowan and its grip is so tight that it has already distorted the swelling trunk of its host, which is still growing rapidly, so .....






































.... if you fast forward a few years, this is the result. This swelling rowan trunk, distorted into a spiral by the tight grip of the honeysuckle, has grown out over the climber's stem, so that it's now embedded inside the trunk of the rowan along part of its length. The rowan has engulf the honeysuckle, but both are still growing well.

One day this might make a good walking stick!




Thursday, November 19, 2015

Unusual Bloomers

Thursday's Guardian Country Diary is about this November-flowering dog rose that we found blooming amongst the rose hips, on a bush growing at Hawthorn Dene on the Durham coast.













The recent record-breaking spell of warm late-autumn weather has extended the flowering period of many plants and even induced some to flower for a second time. Recently we've found holly in bloom and also elder flowers opening alongside berries on the same branch, as well as the usual late-blooming suspects like yarrow, hogweed and clovers. 

This rose was one of two fully-open flowers on a bush covered with ripe rose hips on leafless stems. None of the other roses around it had any flowers. Presumably this individual plant was genetically predisposed to reacting to warmer-than-normal November temperatures. I've seen burnet rose flowering at Christmas in a couple of mild winters but have never seen this kind of behaviour in dog roses.

It seems unlikely that these late flowers will produce seeds because there were no bee pollinators around and the plant had almost no leaves to provide sugars to fill seeds, unlike ...

























... the late-flowering yellow-wort that was blooming at the same site. These flowers were being visited by small fly pollinators that are quite numerous at this time of year and especially attracted to yellow flowers. This species is a fast-growing annual and I suspect that the late-bloomers that we saw might have been second-generation plants themselves, benefitting from the unusually long growing season this year.

Like many annuals, yellow-wort is one of those plants that can grow large and carry scores of flowers in good soil conditions but can also survive in tiny pockets of soil, producing very small plants with just a few flowers and setting seed rapidly when conditions are challenging. Thanks to those fly visitors, the tiny plants flowering in limestone fissures that we found might well produce some viable seeds before winter finally bites.




Saturday, November 14, 2015

Fungi in Auckland Park, Bishop Auckland





















Found some lovely toadstools in Auckland Park at Bishop Auckland last week. I'm pretty sure this is the trooping funnel Clitocybe geotropa - this was the largest in a ring of eleven under a beech tree. Beautiful arrangement of gills under that funnel-shaped cap.















I think this must be hairy curtain crust Stereum hirsutum .......






































.... and this is probably the same species, perhaps paler because the rain had washed out some of the pigment.

Thursday, November 5, 2015

Visit to a tropical coral reef


Bollihope, just south of Frosterley in Weardale, can be a bleak place at this time of year. Acres of brown heather and withered bracken, with a few small conifer plantations. But if you follow some of the burns that flow down into the bottom of the valley you soon find yourself standing on a tropical coral reef, albeit a 325 million year-old one.

This is the subject of Thursday's Guardian Country Diary



































This is the rock known as Frosterley marble, which is not a true marble at all but a fine grained, dark limestone full of fossil Dibunophyllum bipartitum coral. In this slab you can see one almost complete piece of the horn-shaped coral in longitudinal section and two pieces in transverse section. The contrast between the fossil and the stone matrix becomes much greater when you make it wet or polish the surface. 

The state of preservation of the coral structure is astonishing.  This particular specimen is embedded in a slab that must have once been a small waterfall until the burn changed course. It has been worn smooth by flowing water.

Medieval craftsmen spent months cutting and polishing the rock by hand to achieve a smooth, marble like black surface that revealed the fossils in this detail. Their work can be seen in pillars of the Chapel of the Nine Altars in Durham cathedral and in the pillars in the Bishops' Palace at Auckland castle in Bishop Auckland, as well as in smaller objects like the font in Frosterley church. 

It's also in the flagstones on the floor of the bar of the Black Bull pub in Frosterley.

























































































Frosterley marble floor decoration in the Laing Art Gallery, Newcastle-upon-Tyne